Classic auto-correlation techniques are applied in order to detect symbols and/or other meaningful information in a corresponding data stream. Auto-correlation is performed between a presently received wireless signal and a delayed (sampled) version of that signal stored in memory. Generally, such auto-correlation techniques exploit the periodicity structure of the wireless signal during acquisition of an orthogonal frequency-division multiplexing access (OFDMA) signal. In particular, such cyclic prefix based auto-correlators are used during acquisition of a WiMAX downlink signal, as one non-limiting example. As used herein, “WiMAX” and “802.16” respectively refer to signaling standards as defined by the Institute of Electrical and Electronics Engineers (IEEE), Inc., Piscataway, N.J., USA. In particular, the term “WiMAX” refers to IEEE standard 802.16e, as defined in year 2005. The signal periodicity of interest stems from the presence of a cyclic prefix guard interval inherent to the signaling protocol (e.g., WiMAX, 802.16, etc.). In such a case, the distance between correlated signal samples is one orthogonal frequency-division multiplexing access symbol interval, excluding the guard interval.
However, a problem is known to exist under classical auto-correlation strategies. Interference can render the reliable identification of symbols within the received and acquired wireless signal difficult, or in extreme cases, impossible. Various forms of interference as of concern here can be classified as either continuous wave (CW) or direct current (DC) in nature. Continuous wave interference is generally in the form of a constant (or intermittent) radio frequency carrier having no modulation, or modulation that is inconsequential with respect to the sought-after signal (e.g., a WiMAX or 802.16 down link signal, etc.). Direct current interference is typically in the form of a constant, non-oscillating electromagnetic field. In any case, classical auto-correlation of such interference-laden signal samples can result in an unwanted bias that fouls symbol detection and/or identification, rendering wireless communication under the situation difficult, impossible, or unreasonably slow as multiple signaling attempts are required.